CVE-2026-93866— Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Write
Quick assessment
Affected
WatchGuard Fireware OS
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
WatchGuard Fireware OS 的 Access Portal 在 WebSocket 连接处理中存在整数溢出漏洞。当 Access Portal 功能启用时，远程未认证攻击者可通过发送特制请求，导致堆缓冲区越界写入。
Possible ATT&CK Techniques 1 AI
T1190 · Exploit Public-Facing ApplicationAffected Version Matrix 3
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| WatchGuard | Fireware OS | 2025.1< 2026.4 |
affected |
12.0< 12.12.4 |
affected | ||
12.0< 12.5.22 |
affected |
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I. Basic Information for CVE-2026-93866
Vulnerability Information
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Vulnerability Title
Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Write
Source: CVE Program / CVE List V5
Vulnerability Description
An integer overflow vulnerability in the WebSocket connection handling used by WatchGuard Fireware OS's Access Portal allows a remote, unauthenticated attacker to write beyond the bounds of a heap buffer by sending a specially crafted request while the Access Portal feature is enabled.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
整数溢出或超界折返
Source: CVE Program / CVE List V5
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| WatchGuard | Fireware OS | 2025.1 ~ 2026.4 | - |
|
| WatchGuard | Fireware OS | 12.0 ~ 12.5.22 | - |
|
II. Public POCs for CVE-2026-93866
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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Other References for CVE-2026-93866 (1)
-
https://psirt.watchguard.com/CVE-2026-93866 vendor-advisory
Same Patch Batch · WatchGuard · 2026-10-27 · 18 CVEs total
| CVE-2026-103594 | 9.5 CRITICAL | Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution |
| CVE-2026-112709 | 9.2 CRITICAL | Fireware OS Heap Buffer Overflow in AD Authentication Service Allows Pre-Authentication Re |
| CVE-2026-93865 | 9.2 CRITICAL | Fireware OS Missing Authentication in FireCluster Sync Daemon Allows Remote Root Action In |
| CVE-2026-93857 | 9.2 CRITICAL | Fireware OS Pre-Authentication Stack Buffer Overflow in SIP Proxy Allows Remote Code Execu |
| CVE-2026-112710 | 9.2 CRITICAL | Fireware OS Heap Buffer Overflow in AD Authentication Service Allows Pre-Authentication Re |
| CVE-2026-103593 | 9.1 CRITICAL | Fireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Execution |
| CVE-2026-111107 | 8.7 HIGH | Fireware OS NULL Pointer Dereference in Management Interface Allows Unauthenticated Denial |
| CVE-2026-90465 | 8.7 HIGH | Fireware OS Missing Authentication in FireCluster Sync Allows Privilege Escalation |
| CVE-2026-93434 | 8.7 HIGH | Fireware OS XPath Injection in SSH Authentication Allows Blind Extraction of Configuration |
| CVE-2026-90442 | 8.6 HIGH | Fireware OS Authenticated Stack Buffer Overflow in certd Allows Denial of Service |
| CVE-2026-93862 | 7.2 HIGH | Fireware OS Out-of-Bounds Read in FireCluster Sync Allows Denial of Service |
| CVE-2026-90464 | 7.2 HIGH | Fireware OS Missing Command Validation allows Authenticated Arbitrary File Modification as |
| CVE-2026-93864 | 7.1 HIGH | Fireware OS Link Following in firewalld Allows Local Arbitrary File Overwrite as Root |
| CVE-2026-113881 | 6.1 MEDIUM | Fireware OS Stack Buffer Overflow in VPN Network Access Enforcement Allows Unprivileged Co |
| CVE-2026-104381 | 6.0 MEDIUM | Fireware OS Missing Authentication in FireCluster State Sync Allows BOVPN Tunnel Denial of |
| CVE-2026-115495 | 5.7 MEDIUM | Mobile VPN with SSL Client for Windows: Cleartext Transmission of VPN Credentials over Loc |
| CVE-2026-82332 | 5.6 MEDIUM | Fireware OS Improper Authentication in AuthPoint MFA Verification Allows Session Hijacking |
IV. Related Vulnerabilities
Same product: Fireware OS
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CVE-2026-90465
Fireware OS Missing Authentication in FireCluster Sync Allow -
CVE-2026-93862
Fireware OS Out-of-Bounds Read in FireCluster Sync Allows De -
CVE-2026-90442
Fireware OS Authenticated Stack Buffer Overflow in certd All -
CVE-2026-82332
Fireware OS Improper Authentication in AuthPoint MFA Verific -
CVE-2026-103593
Fireware OS Stack Buffer Overflow in Logging Service Allows
Same vendor: WatchGuard
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CVE-2026-115495
Mobile VPN with SSL Client for Windows: Cleartext Transmissi -
CVE-2026-90465
Fireware OS Missing Authentication in FireCluster Sync Allow -
CVE-2026-93862
Fireware OS Out-of-Bounds Read in FireCluster Sync Allows De -
CVE-2026-82332
Fireware OS Improper Authentication in AuthPoint MFA Verific -
CVE-2026-103593
Fireware OS Stack Buffer Overflow in Logging Service Allows
Same weakness: CWE-190
-
CVE-2026-114596
Integer overflow or wraparound in EPICS Base -
CVE-2026-114595
Integer overflow or wraparound in EPICS Base -
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GreycLab CImg through 4.0.6 Heap Out-of-Bounds Read via Inte -
CVE-2026-116840
llama.cpp b5854 before b11275 Integer Overflow in gguf_init_